// e1.groovy
/*
If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Find the sum of all the multiples of 3 or 5 below 1000.
*/
sum = 0
for (n in 3..999) { 
    if ((n % 3 == 0) || (n % 5 == 0)) sum += n
}
assert 233168 == sum

